Please check have you set the hotspot right. Here is the step for you.
Settings – more – tethering & portable hotspot – wifi hotspot – turn on – set up wifi hotspot – slip down and then click “show password”.
Then you could see the password on the phone. If you want a easy remember password, you could edit it and save again.
Later on, please search it on another smart phone. If it can be find, then it works. Otherwise, it means the two device is not compatible.